Chevy and GMC Duramax Diesel Forum banner
1 - 20 of 527 Posts

·
Registered
Joined
·
6 Posts
LMM mpg

Have a crew cab 4wd, only 500 miles on it, so far 15.4 towing a bass boat and 16 mpg combined highway and in town. Just put diesel kleen in a fresh tank of fuel, so no results yet from that.

I'm sure mileage will increase once broken in and if I can keep my foot out of that torque.

Mike
 

·
Registered
Joined
·
17 Posts
I have A 07 LMM Crew Cab Z71 just tagged it today so had it about 4 weeks. I have just over 5000 miles on it. On my first trip all highway I was seeing 18 mpg.
In town and highway I see around 16. It is still Bone stock.
 

·
Registered
Joined
·
17 Posts
Just got home from a trip to South Fork, Co. about a 1200 mile round trip. Pulled a 28ft 5th wheel with 2 slide out not sure on the weight.. Got 15mpg on the trip. Have 8300 miles on truck.
 

·
Registered
Joined
·
6 Posts
Have 1500 miles on the 07 LMM crewcab now, getting 19mpg all highway and 16mpg in town, up from previous posting mpg. Still using power service fuel treatment, summer blend at the minimum amount.

The 19mpg was at 68mph average, nothing being towed.

Mike
 

·
Registered
Joined
·
164 Posts
Crew cab 4x4, 3/4 ton, Duramax with Alli, 12 mpg towing my 16ft enclosed landscaping trailer, 14 to 15 mpg when empty. I have been taking it easy on the truck, I have not even had it to 75 mph yet.Maybe she will get better!:rockin
 

·
Registered
2021 GMC Denali CC Dually & 2006 GMC 3.0 limited pro Cummins Powered
Joined
·
84 Posts
I was getting 15.7mpg empty and 8.8mpg with the truck and trailer. I just cut out the fins in the air box and the last trip I did I got 18.2mpg. The 15.7 mpg was one day before I cut the fins out. The truck has 500 miles on it.
 

·
Registered
2021 GMC Denali CC Dually & 2006 GMC 3.0 limited pro Cummins Powered
Joined
·
84 Posts
what are you talking bout cutting the fins out?

Take the baffle out of the airbox and cut the fins out, I used a rotozip to do this. The air box just pulls right out. Just have to take the hose clamp off. It really works.
 

·
Diesel Addict
Joined
·
7,754 Posts
I cut the fins out today and put a K&N in place of the factory air filter. I hope this will help the mpg.!
please do your self a favor and install the oem filter again or a AFE,Volant,S&B or a Amsoil filter but anytning but the K&N the reason i say that they allow to much dirt into the turbo housing ruining the bearings and after awhile you will need a new turbo..
 

·
Registered
Joined
·
6 Posts
Yeh, take that K&N out as fast as you can or you will trick, ruin, trash your mass air flow sensor, not only do K&N's not filter good, but they deposit oil all over the mass air flow sensor, screwing up your mileage, throwing codes, etc.. The gasoline rodders experienced that pain several years ago. Like the previous thread said, go with oem or the other none oiled filters. If your K&N has already oiled the mass airflow, there is a specific cleaner for getting the oil off of it.
 
1 - 20 of 527 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top